Off-the-road (OTR) tires include tires for construction vehicles such as wheel loaders, backhoes, graders, trenchers, and the like, as well as large mining trucks. OTR tires can be of either bias or radial construction, although the industry is trending toward increasing use of radial. Bias OTR tires are built with a large number of reinforcing plies to withstand severe service conditions and high loads.
Disposal of large diameter OTR tires used in construction and mining is a growing, global concern. The physical properties of OTR tires differ significantly from passenger and truck tires, and require specialized processes to ensure a safe and cost-effective means to reduce the overall mass to a workable size for further processing. For perspective, a typical truck tire may weigh one hundred thirty pounds and measure forty two inches in diameter. However, a typical OTR tire weighs around seven thousand pounds and measures nearly twelve feet in diameter. OTR tires also have very large steel beads disposed within the edges of the central tire openings that provide stability to the sidewalls and seal the tire to the rim. In some instances, the beads may account for up to five percent of the total tire weight.
The large steel beads located in the OTR tires represent a distinct problem for tire recyclers. There are some tire shredding machines capable of cutting through these large beads; however, this significantly increases the wear and maintenance costs of the equipment. By removing the bead prior to shredding, tire recyclers are able to reduce these costs and increase the life of their equipment.
Previous owners of scrapped OTR tires face a different problem. Many do not want the tires to be repaired and re-used in order to mitigate potential liability that could arise over defective tires. Most damaged OTR tires can be repaired as long as the casing and bead are still in reasonably good condition. Occasionally, tires will be repaired and resold without the prior owner's knowledge. However, an OTR tire cannot be repaired if the bead has removed. Accordingly, a cost effective method of removing the beads from OTR tires would be desirable to owners of scrapped OTR tires who do not want the tires to be repaired or reused. Presently, there are no machines on the market that are capable of removing the whole bead from an OTR tire.